The present invention relates to processes and apparatuses for forming golf balls, and more particularly to processes and equipment for forming golf balls having one or more deep dimples that extend through a cover layer to and/or into one or more layers or components thereunder. The present invention also relates to processes and apparatuses for forming golf balls with deep dimples by utilizing one or more specifically tailored xe2x80x9cknock-outxe2x80x9d pins that serve to support the core or ball assembly during molding, assist in removing the molded ball from the mold, and form deep dimples in the ball. These particularly tailored pins are preferably used in conjunction with other features in the mold to form deep dimples in the resulting ball. The various processes and apparatuses described herein are particularly well suited for use in conjunction with reaction injection molding techniques.
A number of two-piece (a solid resilient center or core with a molded cover) and multi-layer (liquid or solid center and multiple mantle and/or cover layers) golf balls have been produced. Different types of materials and/or processing parameters have been utilized to formulate the cores, covers, etc. of these balls, which dramatically alter the balls"" overall characteristics. In addition, multi-layer covers of different materials have also been formulated in an attempt to produce a golf ball having the overall distance, playability and durability characteristics desired.
For certain applications it is desirable to produce a golf ball having a very thin cover layer. However, due to equipment limitations, it is often very difficult to mold a thin cover. Accordingly, it would be beneficial to provide an apparatus and technique for producing a relatively thin outer cover layer.
Moreover, retractable pins have been utilized to hold, or center, the core or core and mantle and/or cover layer(s) in place while molding an outer cover layer thereon. However, these pins have only been utilized to support the core during molding and have not contributed to the outer appearance of the ball. In fact, conventional pins sometimes produce centering difficulties and cosmetic problems (i.e. pin flash, pin marks, etc.) during retraction, which in turn require additional handling to produce a golf ball suitable for use and sale. Accordingly, it would be desirable to provide an apparatus and method for forming a cover layer on a golf ball with retractable pins that overcame the problems associated with conventional pins.
One aspect of the present invention is to provide equipment and methods for forming a golf ball with a thin cover that has a favorable combination of playability properties yet which may be manufactured more cost effectively and without many of the problems associated with prior balls.
Yet another aspect of the invention is to provide equipment and methods for forming a golf ball having one or more deep dimples and a resulting favorable combination of spin, resiliency and durability characteristics.
A further aspect of the invention is to provide equipment and methods for forming a golf ball having a dimpled cover that is thinner than traditional cover layers with one or more deep dimples.
Another aspect of the invention is to provide equipment and methods for forming a golf ball having dimples in an outer cover layer that extend to, and/or into at least the next inner layer of the ball.
Yet another aspect of the invention is to provide equipment and methods for forming a golf ball core or intermediate ball assembly that in many instances may be readily removed from a molding assembly.
Another aspect of the invention is to provide novel molding equipment that simplifies manufacturing of golf balls and components thereof. The equipment utilizes one or more specifically tailored xe2x80x9cknock-outxe2x80x9d pins that serve to support the core or ball during molding, assist in removing the molded ball from the mold, and form deep dimples in the ball. These particularly tailored pins are preferably used in conjunction with other features in the mold to form deep dimples in the resulting ball.
In a further aspect, the present invention provides a molding apparatus adapted for forming a golf ball having one or more deep dimples. The apparatus comprises an upper mold having a first hemispherical molding surface that defines a hemispherical molding cavity, and at least one aperture defined along the first molding surface. The upper mold further has, in each of the apertures, a selectively positionable pin having a distal end that may be extended into the cavity or retracted from the cavity. The molding apparatus further comprises a lower mold having a second hemispherical molding surface that defines a hemispherical molding cavity and at least one aperture defined along the second molding surface. The lower mold further has, in each of the apertures, a selectively positionable pin having a distal end that may be extended into the cavity or retracted therefrom. The upper mold and the lower mold are adapted to engage each other such that the first molding surface and the second molding surface form a generally spherical molding chamber. The pins in each of the apertures defined in the upper mold and lower mold extend into the molding chamber a distance of from about 0.002 inches to about 0.140 inches as measured from the respective first or second molding surface. The pins remain in the extended position during a molding operation so as to form a corresponding number of deep dimples in the resulting golf ball.
In another aspect, the present invention provides a molding apparatus adapted to form a golf ball with a plurality of deep dimples along an outer surface of the ball. The apparatus comprises a first mold including a first hemispherical molding surface defining a first molding cavity and at least one aperture defined along the first molding surface. The first molding surface has at least one raised protuberance adapted to form a deep dimple. The first mold further includes, in each of the apertures, a selectively positionable pin having a distal end that may be extended into the first cavity or retracted from the first cavity. The molding apparatus further includes a second mold having a second hemispherical molding surface that defines a second molding cavity and at least one aperture defined along the second molding surface. The second molding surface has at least one raised protuberance adapted to form a deep dimple. The second mold further includes, in each of the apertures, a selectively positionable pin having a distal end that may be extended into the second cavity or retracted from the second cavity. The first mold and the second mold are adapted to engage each other such that the first molding surface and the second molding surface form a generally spherical molding chamber. At least a portion of the raised protuberances in the first and second molding surfaces have a height, as measured from their respective molding surface, of from about 0.002 inches to about 0.140 inches.
In yet another aspect, the present invention provides a molding apparatus adapted for forming a golf ball with a plurality of deep dimples along an outer surface of the golf ball. The apparatus comprises a first mold including a first hemispherical molding surface defining a first molding cavity and at least one aperture defined along the first molding surface. The first molding surface has at least one raised protuberance adapted to form a deep dimple. The first mold further includes, in each of the apertures, a selectively positionable pin having a distal end that may be extended into the first cavity or retracted from the first cavity. Each of the pins associated with the first mold are positionable such that the distal end extends into the first molding chamber a distance of from about 0.002 inches to about 0.140 inches as measured from the first molding surface. The molding apparatus further comprises a second mold including a second hemispherical molding surface defining a second molding cavity and at least one aperture defined along the second molding surface. The second molding surface has at least one raised protuberance adapted to form a deep dimple. The second mold further includes, in each of the apertures, a selectively positionable pin having a distal end that may be extended into the second cavity or retracted therefrom. Each of the pins associated with the second mold is positionable such that the distal end of the pin extends into the second molding chamber a distance of from about 0.002 inches to about 0.140 inches as measured from the second molding surface. Each of the first and second molds are adapted to engage each other such that the first molding surface and the second molding surface form a generally spherical molding chamber. At least a portion of the raised protuberances in the first and second molding surfaces have a height, as measured from their respective molding surface, of from about 0.002 inches to about 0.140 inches.
In yet a further aspect, the present invention provides a process for forming a golf ball having a plurality of deep dimples. The process comprises a step of providing a molding apparatus having an upper mold including a first molding surface that defines at least one aperture. The upper mold further includes a selectively positionable pin in each of the apertures. The molding apparatus also includes a lower mold including a second molding surface that defines at least one aperture and also including a selectively positionable pin in each of the apertures. The pins of the upper and lower molds have a distal end that may be extended past the respective first and second molding surfaces. The upper and lower molds are adapted to engage each other such that the first molding surface and the second molding surface form a generally spherical molding chamber. The process also comprises a step of positioning a golf ball core or intermediate ball assembly within the molding chamber. The process includes an additional step of extending at least one the pins within the molding chamber so that the distal end of the extended pin contacts the golf ball core assembly or intermediate ball assembly. The process includes an additional step of introducing a molding material within the molding chamber and around the golf ball core or intermediate ball assembly to thereby form a layer of material around the golf ball core or intermediate ball assembly. The process includes another step of at least partially hardening the molding material. And, the process includes a step of retracting the pins to thereby form deep dimples in the resulting layered core or ball assembly.
In yet another aspect, the present invention provides a process for forming a golf ball having a plurality of deep dimples. The process comprises a step of providing a molding apparatus having an upper mold including a first molding surface that defines a first raised protuberance adapted to form a deep dimple and at least one aperture. The upper mold includes a selectively positionable pin in each of the apertures. The molding apparatus includes a lower mold having a second molding surface that defines a second raised protuberance adapted to form a deep dimple and at least one aperture. The lower mold further includes a selectively positionable pin in each of the apertures. The pins of the upper and lower molds have a distal end that may be extended past the respective first and second molding surface. The upper and lower molds are adapted to engage each other such that the first molding surface and the second molding surface form a generally spherical molding chamber. The process includes a step of positioning a golf ball core or intermediate ball assembly within the molding chamber. The process includes another step of extending at least one of the pins within the molding chamber so that the distal end of the extended pin contacts the golf ball core or intermediate ball assembly. The process further includes a step of introducing a molding material within the molding chamber and around a golf ball core or intermediate ball assembly to thereby form a layer of the molding material around a golf ball core or intermediate ball assembly. The process includes a step of at least partially hardening the molding material. And, the process includes a step of retracting the pins to thereby form additional deep dimples in the resulting layered core or ball assembly.
The invention accordingly comprises several apparatuses, processes, compositions, components and steps and the relation of one or more of such apparatuses, processes, compositions, components and steps with respect to each other. Moreover, the invention is directed to articles possessing the features, properties, and the relation of elements exemplified in the following detailed disclosure.